[Android] Update kotlinx-coroutines verison

[Geoffrey Métais]

vlc-android | branch: master | Geoffrey Métais <geoffrey.metais at gmail.com> | Tue Jan 16 13:25:21 2018 +0100| [0a47f2b7d025b09e1390b609abe17ee543859777] | committer: Geoffrey Métais

Update kotlinx-coroutines verison

> https://code.videolan.org/videolan/vlc-android/commit/0a47f2b7d025b09e1390b609abe17ee543859777
---

 build.gradle | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/build.gradle b/build.gradle
index be0b84ce6..dbf01dd38 100644
--- a/build.gradle
+++ b/build.gradle
@@ -2,7 +2,7 @@
 buildscript {
     ext.android_plugin_version = '3.0.1'
     ext.kotlin_version = '1.2.10'
-    ext.kotlinx_version = '0.20'
+    ext.kotlinx_version = '0.21.2'
     repositories {
         flatDir dirs: "gradle/plugins"
         google()